1. Field of the Invention
The present invention relates to a rechargeable battery abnormality detection apparatus to detect battery cell internal short circuit abnormalities, and to a rechargeable battery apparatus provided with that abnormality detection apparatus.
2. Description of the Related Art
Rechargeable batteries such as lithium ion rechargeable batteries are used as a power source for various types of electronic equipment by connecting a plurality of battery cells in series in accordance with the power source specifications of the electronic equipment. In these cases, rechargeable battery charging and discharging are controlled consistent with battery voltage, charging capacity, and remaining discharge capacity. Further, rechargeable battery abnormality can be detected and battery use prohibited, or depending on the degree of battery degradation, the existing rechargeable battery characteristics can be utilized in an optimal fashion.
One example of the treatment of a detected rechargeable battery abnormality is suggested in Japanese Patent Application 2007-243049 previously submitted by the present applicant et al. Here, internal short circuit (so-called micro-short) caused by a defect within a battery cell is detected, and use of the rechargeable battery with the internal short circuit is prohibited. As an example of a technique for control depending on the degree of rechargeable battery characteristic degradation for the case of rechargeable battery performance (charging capacity) degradation, charging with a lower current to increase charging is recommended.
For example, refer to US Patent Application Disclosure 2007/0139008.